Table 4.

Segregation of the HR and Resistance to TCV in a Cross between Di-17 and npr1-1, npr1-5, etr1-1, or coi1-1 Mutants^d

Crossa	Generation	Total No. of Plants	Genotype at NPR1, ETR1 or COI1 Locib	Phenotype of Plantsc				χ2d	Pe
				HR+/Sf	HR+/Rg	HR−/S	HR−/R
Di-17 × npr1-1 (Col-0)	F1	2	NPR1/npr1-1 (2)	2	0	0	0
	F2	121	npr1-1/npr1-1 (15)	11	2	2	0
Di-17 × npr1-5 (Nö)	F2	237	npr1-5/npr1-5 (41)	22	9	10	0	0.274	>0.8
etr1-1 (Col-0) × Di-17	F1	4	ETR1/etr1-1 (4)	4	0	0	0
	F2	102	ETR1/etr1-1 plus
			etr1-1/etr1-1 (74)	44	14	16	0	0.462	>0.8
coi1-1 (Col-0) × Di-17	F1	4	COI1/coi1-1 (4)	4	0	0	0
	F2	137	coi1-1/coi1-1 (38)	21	6	11	0	0.413	>0.8

^aThe pollen-accepting plant is indicated first and the pollen donor second.

^bThe genotype at the NPR1, COI1, and ETR1 loci were determined by CAPS analysis. The total number of plants of the given genotype that were analyzed for the HR and resistance to TCV is given in parentheses.

^cCAPS analysis indicated that all TCV-resistant plants contained at least one copy of the dominant HRT allele, whereas all HR⁻-susceptible plants were homozygous for the recessive hrt allele. Except for the Di-17 × npr1-1 cross, which showed skewed segregation of the HRT locus similar to the Di-17 × Col-0 cross (Table 2), the rest of the other crosses showed 1:2:1 Mendelian segregation of the HRT locus (data not shown).

^dCalculation based on a 9:3:4 ratio.

^eTwo degrees of freedom.

^fS, susceptible; disease symptoms include crinkling of leaves and drooping of the bolt.

^gR, resistant; no disease symptoms.